The main objective of this proposal is to study the effect of early intervention of age-related arterial changes on the incidence of atherosclerosis in the spontaneously atherosclerosis-susceptible White Carneau pigeon. The intervention procedures to be tried are: 1) underfeeding; 2) feeding of cholestane-3 beta, 5 alpha, 6 beta-triol; 3) intestinal bypass surgery; and 4) administration of estrogens (shown to inhibit smooth muscle cell proliferation). The effect of these intervention programs started at 1 month of age on the a) incidence of atherosclerosis; b) sterol and steryl ester chemistry of the aorta; c) structure of the aorta; d) plasma cholesterol: and e) total sterol balance would be determined. The study would provide crucial information whether the intervention of age-related changes early in life can modify the subsequent occurrence of degenerative disease in the aorta.